DIGGER WASP, CICADA-KILLER (Sphecius speciosus).
This is a very large
wasp, 11/4 inches long, black with the abdomen banded with yellow
and a wickedly long, curved ovipositor or stinger. Appearing in mid and
late summer this wasp makes a mess of lawns, tunneling far underground
and marking the openings to its burrows with little mounds of earth.
I have seen it abundant enough to lift and crack concrete sidewalks with
its tunnels and mounds, to say nothing of scaring to death all the
passers-by. After making her burrow, the female goes hunting for a
cicada; she darts at it in the tree and they both fall to the ground; then
she paralyzes it by stinging. Although the cicada is a lot bulkier than the
wasp, she straddles it and crawls up a tree to get a vantage point from
which to glide toward her burrow. If she does not make it the first time,
she tries another tree and a second glide. Then she drags her victim
inside the burrow, lays an egg in it, seals off the walls and repeats the
performance. The larvae hatch in a few days, suck on the cicada for a
couple of weeks and then rest in a cocoon until the next summer.
Control. Injecting carbon bisulfide into the burrows from a machine-oil
can and plugging the openings with earth is quite helpful. So is batting
the creatures to death with a giant fly-swatter made by fastening a square
of wire mesh on a stout stick. I have not been stung doing this, but I
shudder when I see those giant stingers zooming close to my head. DDT
or chlordane dust in and around the burrows should be fairly satisfactory.
GIANT HORNET (Vespa crabro germand).
This is our largest hornet, an
inch long, dark reddish brown with yellow markings, stouter and
more hairy than the digger wasp and without such a terrifying ovipositor.
It appears in late summer, tearing the bark off lilac trunks and branches
in irregular rings an inch or more wide (Figure 59B), sometimes defacing other shrubs. It seems impossible that a wasp can gnaw and tear the
bark in such fashion; unless you see it in action you would swear the
damage was due to squirrels. Vespa uses this bark acquired so ruthlessly
to make brown paper nests under eaves of buildings, in hollow trees,
or other sheltered places. She can do a lot of harm in a short time for
branches die back to the girdled area.
Control. Painting lilac trunks and branches with DDT will protect
them. Stir a tablespoon of the wettable powder into a pint of water and
apply with a paint brush. This is, of course, much stronger than the
dilution for regular spraying.